This invention relates to keyboards, particularly ones suited for use with one hand. The invention uses color coding to reduce the number of keys on the keyboard to make it suitable for one hand.
The need for a one-handed keyboard has long been recognized. A one-handed keyboard was developed in U.S. Pat. No. 3,833,765, to Hilborn et al. for use by aircraft controllers who greatly benefit from having only one hand occupied. This keyboard uses a large number of key combinations based on the ICAO phonetic alphabet. Another device specifically designed for word processing was developed by Endfield in U.S. Pat. No. 4,360,892. Endfield's device uses key arrangements that vaguely suggest the shape of letters. This device uses only six keys and would require considerable training to use effectively.
A one-handed keyboard developed by Bequaert et al. in U.S. Pat. No. 4,042,777 uses spatial relationships shown on the keys to provide the necessary number of combinations to complete a set of alphanumeric characters. This requires a considerable amount of printing on its small keys to identify the character which results from each combination. To obtain any of the large number of combinations, fingers press more than one key at a time. The thumb may press either of four keys or any two adjacent keys while a finger concurrently presses one key, two keys next to each other or is positioned at the intersection of four adjacent keys to press all four at once.
Another solution to the one-handed keyboard problem was made by Prame in U.S. Pat. No. 4,381,502. This device uses sequence recording circuitry to obtain its increased number of combinations. For instance if Key B is pressed after Key A, a different character will be produced than if Key A is pressed after Key B.
An expanding need for one-handed keyboards is expected. The miniaturization of computing equipment is leading to the production of pocket-sized telecomputing systems. Attempts are being made to put full typewriter keyboards into such a pocket sized device, however, these are very difficult to use because of the small size and proximity of the keys. Therefore, a method has been needed for reducing the number of keys on a telecomputing system so that it can be easily operated. Once this has been done, telecomputing systems can be widely used to send and receive messages and perform simple computing tasks while being both easily portable and operable with one hand.
The preferred embodiment of the present invention uses color coding to reduce the number of keys. In an early keyboard color arrangement pattern, Allen, in U.S. Pat. No. 706,002, developed a keyboard that associated key colors with letter combinations. In 1919, U.S. Pat. No. 1,319,687, to Bates, used colors as an aid in teaching touch typewriting with a different color for each finger stall. This was also pursued by Bloem in French Patent No. 716,957 which used colored keyboards as a teaching heuristic.
None of the above keyboards has reduced the number of keys on a one-handed device in such a way as to enable any person who picks up the device to access the entire set of alphanumeric characters without significant training.